METHOD FOR PRODUCE A SHAFT WINDING WITH BARRED WIRE ENDS

Description

[0001] The invention relates to a method for producing a wave winding with stripped wire ends.

[0002] Numerous processes have been developed for manufacturing high-efficiency rotors or stators, primarily focused on producing continuous coil windings. These windings are produced as flat mats and then inserted into slots in the stators or rotors. The windings consist of a number of interwoven wires, which are bent multiple times in opposite directions. This results in parallel legs or straight sections of wire, intended to fill the slots, being connected by roof-like winding heads that project beyond the ends of the rotors or stators. A flat, rotatable winding template and a wire handling device can be used to produce the coil winding as a flat mat. A winding mat produced in this way is also called a wave winding.DE 10 2015 120 661 A1 describes a method for manufacturing such a wave winding. A wave winding is characterized by the fact that the open wire ends of the individual wires formed into the wave winding are arranged either at both ends of the wave winding or at one end of the wave winding. DE 10 2020 130647 A1, for example, shows an arrangement in which the wire ends of the wave winding are already stripped.

[0003] The shaft winding is transferred from the winding template into a rotor or stator body by means of a transfer device. DE 10 2015 120 963 A1 discloses a transfer device according to the prior art. The transfer device has a circulating link chain which is deflected over pulleys and linearly tensioned, so that in an area between the winding template and a transfer point to a transfer tool the winding can be flattened and transported without bending.

[0004] In another variant, a linear magazine is used to transfer the wave winding from the winding blade to the insertion tool; the entire winding mat is transferred into this magazine and then removed again for insertion into the insertion tool.

[0005] To enable electrical flow in the coil of an electric motor, different wire ends must be connected to allow electrical flow for different phases. The wires used to manufacture the wave winding have an insulating protective layer that must be removed before contacting. US 2015 336 214 A and US 2019 326 801 A show that the wire ends are stripped while the coil is inserted into the stator. Stripping while the coil is inserted causes undesirable contamination of the stator, which is difficult to control. To avoid this, masking can be used, but this is very complex and potentially expensive. Furthermore, the additional step, which may require manual handling, can increase the cycle time in manufacturing.Furthermore, the accessibility of the wire ends may be severely restricted, for example by overlapping layers on the stator's inner and outer diameters, which hinders both the stripping process and clamping and gripping technology.

[0006] Alternatively, stripping of the insulation can be performed on exposed individual wires before the winding is inserted. US 2013 031 779 A shows stripping before the individual wire is cut to length, and US 2019 280 574 A shows stripping after the individual wire has been cut to length. Stripping the individual wires results in insulation being applied relatively early in the process chain, up to the point of contacting the wire ends. Due to tolerances in coil manufacturing, this leads to inaccuracies in the actual length of the exposed wire ends, which cannot be easily corrected without further stripping. Furthermore, there is an increased risk of recontamination of the copper surface during the process chain up to the point of contacting the wire ends.

[0007] The object of the invention is to provide a method that eliminates the aforementioned disadvantages and also provides a simplified process for accurately stripping the wire ends.

[0008] The method according to claim 1 is provided for solving the problem. Further embodiments are described in the dependent claims.

[0009] According to the invention, the following process steps are provided for a method for stripping wire ends of a wave winding: winding a wave winding from parallel, insulated individual wires on a flat winding template around a winding axis, transferring the wound wave winding into a linear magazine, moving the linear magazine in a conveying direction until the open wire ends come to rest within a respective process window; and removing insulation from the individual wires in the area of ​​the wire ends protruding laterally from the linear magazine.

[0010] Removing the insulation from the exposed wire ends of the individual wires, allowing the wire ends to protrude laterally beyond the winding template or linear magazine, offers the advantage of easy access to the wire ends. There are no disruptive overlaps of the wire ends, as would be the case, for example, when the wire is drawn in. Furthermore, any remaining insulation can be easily removed, effectively preventing contamination of the wave winding with insulation residue. Since the exposed wire ends of the individual wires protrude laterally beyond the winding template, it is also conceivable that the insulation removal can take place while the wave winding is still wound onto the template. This could occur, for example, during the winding process or immediately after the wave winding is completed on the template.

[0011] According to a further development of the method, the insulation removal by laser ablation takes place within a process window. Here, the process window is a spatial area within which the insulation can be removed. More than one process window can also be provided for insulation removal. Wave windings are elongated winding mats, and it is possible for all open wire ends to be arranged at one end relative to a longitudinal axis of the winding mat. Likewise, the open wire ends can be arranged at both ends of the winding mat. In this case, two process windows can be provided within which the insulation is removed.Laser ablation is the preferred method because the removal tool (the laser optics) is essentially wear-free and the energy input can be optimally adjusted to the insulation to be removed, so that damage to the actual wire being stripped can be largely avoided.

[0012] In the event that several process windows are provided for the removal of the insulation, either several devices for removing the insulation can be provided accordingly, or the process windows or the devices can be moved accordingly so that several process windows can be operated with one device.

[0013] Accordingly, one embodiment of the method provides that during the removal of the insulation, a relative movement takes place between the radiation outlet of a laser source and the wave winding. The radiation outlet of the laser source can be movable relative to the wave winding, and / or the wave winding can be movable relative to the radiation outlet of the laser source. In a preferred embodiment, the radiation outlet of the laser source can be moved around the laterally protruding wire ends.

[0014] Accordingly, a further development reveals that the radiation output is designed to move axially to a longitudinal axis of the wave winding. In an advantageous embodiment, the relative movement is parallel to the longitudinal axis of the wave winding, and the radiation output of the laser source can be arranged at a distance from a center line of the wave winding. Furthermore, an advantageous embodiment allows the radiation output of the laser source and / or the wave winding to be movable relative to each other in several degrees of freedom.

[0015] It can also be provided that the angle of incidence of the radiation exiting the radiation outlet and striking the wire ends within the process window is varied during stripping. In a preferred embodiment, the angle of incidence is 45°. This can preferably be achieved by a radiation outlet that is rotatable about an axis of rotation.

[0016] According to the invention, the shaft winding is transferred from the winding template to a linear magazine before the insulation is removed. The use of a linear magazine advantageously ensures a defined position of the shaft winding and, in particular, the wire ends. The process windows can preferably be defined with respect to their position relative to the linear magazine, thus simplifying the process sequence. If a linear magazine is used, the relative movement described above can be achieved by the conveying movement of the linear magazine during its filling or by the movement of a filling tool for the linear magazine.

[0017] A further development of the invention provides that, prior to removing the insulation, the wave winding is assembled into a complex winding mat within the linear magazine. A complex winding mat can be created by several wave windings being inserted into the linear magazine, either one above the other or interwoven.

[0018] According to one embodiment of the method, the shaft winding or winding mat can be shaped before or after the insulation is removed. A further process step, in which the winding mat is shaped, for example by pressing or rolling, levels the height of the winding mat, thus facilitating its installation in a rotor body, stator body, or its transfer into a drawing-in tool. This is also advantageous if the insulation still needs to be removed, because the shaping process ensures that the wire ends also assume a defined position, preferably within the process window(s).

[0019] In accordance with the foregoing, it is advantageous that an optional further development of the method provides for the transfer of the shaft winding or the winding mat into a rotor body or a stator body or a drawing-in tool after the removal of the insulation.

[0020] Finally, it can be further specified that the wire ends are shortened before or after the insulation is removed. In this way, the wire ends can be prepared for the desired installation situation without the disadvantages described above also occurring for the wire sections.

[0021] Further features, details and advantages of the invention will become apparent from the wording of the claims as well as from the following description of exemplary embodiments based on the drawings.

[0022] The figures show: Fig. 1: a schematic representation of a winding mat inserted into a linear magazine; and Fig. 2: a schematic representation of the relative movement of a laser optic in relation to the wire ends in a sectional view.

[0023] Figure 1 Figure 1 shows an embodiment of the method in which insulation can be removed from wire ends 22, 24 of a wave winding 20 inserted into a linear magazine 10 in a first process window 32 and in a second process window 34.

[0024] The linear magazine 10 is moved in a conveying direction R, which runs parallel to a longitudinal axis L of the wave winding. It can be seen that the wire ends 22, 24 protrude laterally from the linear magazine 10. The movement of the linear magazine 10 in the conveying direction R brings the wire ends 22, 24 into an area where the respective process window 32, 34 is located. In this embodiment, the wave winding 20 is manufactured such that, with respect to the longitudinal direction of the wave winding 20, the wire ends 22, 24 protrude laterally at both ends of the wave winding 20.

[0025] Figure 2Figure 1 shows a side view of how a radiation outlet 42 of a laser source 40 or a laser optic is moved relative to the wire ends 22 in one of the process windows 32, 34. The radiation outlet 42 has an angle of inclination such that the laser beam 46 strikes the respective wire end to be stripped at an angle of incidence 44. The laser beam 46 is moved at an angle of incidence 44. Figure 2 The depicted movement path B of the laser source 40 or the radiation outlet 42 shows that the insulation of the wire ends 22 can be ablated in the cross-section all around by means of the laser source 40 or the radiation outlet 42. It is understood that the angle of incidence 44 can be adjusted by adjusting the laser source 40 or the radiation outlet 42 or by rotating the laser source 40 itself.

[0026] All features and advantages arising from the claims, the description and the drawing, including design details, spatial arrangements and process steps, can be essential to the invention both individually and in various combinations. Reference symbol list

[0027] 10 Linear magazine 20 wave winding 22, 24 wire ends 32, 34 Process window 40 Laser source 42 Radiation exit 44 Angle of incidence 46 Laser beam B Movement path L Longitudinal axis R Conveyor direction

Claims

1. A method for stripping wire ends (22) of a wave winding (20), having the following method steps: - winding a wave winding (20) from parallel, insulated individual wires onto a flat former (100) about a winding axis, with open ends (22) of the individual wires laterally protruding over the former; CHARACTERISED BY the following method steps: - transferring the wound wave winding (20) into a linear magazine (10); - moving the linear magazine (10) in a conveying direction (R) until the open wire ends (22) come to rest within a respective process window (32, 34); and - removing any insulation from the wire ends (22) protruding from the side of the linear magazine.

2. The method according to claim 1, wherein the removal of the insulation takes place by means of laser ablation within a process window (32, 34).

3. The method according to claim 2, wherein during the removal of the insulation, a relative movement takes place between a radiation outlet (42) of a laser source (40) and the wave winding (20).

4. The method according to claim 3, wherein the radiation outlet (42) is moved axially to a longitudinal axis (L) of the wave winding (20).

5. The method according to claim 2 to 3, wherein the angle of incidence (44) of the radiation emanating from the radiation outlet (42) and impinging on the wire ends (22) within the process window (32, 34) is varied during stripping.

6. The method according to any one of the preceding claims, wherein, before the removal of the insulation, the wave winding (20) is joined to form a complex winding mat within the linear magazine (10).

7. The method according to any one of the preceding claims, wherein, before or after the removal of the insulation, the wave winding (20) or the winding mat is shaped.

8. The method according to any one of the preceding claims, wherein, after the removal of the insulation, the wave winding (20) or the winding mat is transferred into a rotor body or a stator body or a drawing-in tool.

9. The method according to any one of the preceding claims, wherein, before or after the removal of the insulation, the wire ends (22) are shortened.